Casing head



Nov. 11, 1952 J, w, THAT H 2,617,485

CASING HEAD Filed March 11. 194'? 2 SHEETS-SHEET l 38b 66 50 s5 s7 68Eaawmmma INVENTOR. JOHN W. THATCH BY WW rm ATTORNEYS Nov. 11, 1952 J. w.THATCH 2,617,485

CASING HEAD 1 Filed March 11, 1947 2 SHEETS-SHEET 2 s3 3 82 I 92 8 W 93,INVENTOR. JOHN w. THATCH ATTORNEYS Patented Nov. 11, 1952 UNITED STATESPATENT OFFICE CASING HEAD John w. Thatch,. Wilmington, Califz, assignorm Regan Forge; and Engineering, Company, San Pedro, Calif., acorporation of California Application March 11, 1947'; Serial No.-733,780

3 Claims. (01. 166-14) This invention relates generally to casing andtubing heads used in. oil. wells.

It is an object of this invention to provide a novel casing and tubinghead means particu larly suitable for use in producing wells where highfluid pressures are present, either from natural causes or as a resultof artificial causes, such as in. the production methods utilizing highpressure fluids injected into the wells.

It is a particular object of the invention to provide a casing andtubing head structure embodying means for effecting a seal betweenthehead structure and the outer surface of an inner string of easing at.two spaced points located one in each of two adjoining head members inwhich the sealing means is. so. related. to the. other parts of thestructure that it is readily accessible- In this connection it is anobject-to provide a casing and tubing head structure embodying means forsuspending an. inner casing. from a point in the lowermost of the twoheads at a point below the seal means therein.

More particularly, it is an object to provide a casing head structureembodying adjoining connected head members and having a sealing orpacking means in the lower part of the upper-- most of the two headmembers and a sealing or packing means in the upper part of. thelowermost head member, together withv means in the lowermost head memberbelow the sealing means therein for suspending the inner casing againstwhich the seals pack off.

It is also an object to provide a construction of the type indicatedwherein it is possible to test the effectiveness of each seal means forthe casing and additionally the eiiectivenessof the joint between thetwo head members.

It is a further object of the invention to provide a casing headstructure of the type: indicated, which may readily be assembled aboutthe upper end of a casing or tubing.

It is also an object of the invention to provide, in a head of the typeindicated, means for adjusting the sealing means within the head from apoint outside the head.

These and other objects will be apparent from the drawings and thefollowing description thereof. Referring to the drawings, which aremerely for illustrative purposes:

Fig. 1 is an elevational view partly in section of a casing andtubinghead structure embodying the invention;

Fig. 2 is a fragmentary elevational view,v partly in section, of atubing head structure embodying a different form of the invention; and

Fig. 3 is an elevational view, partly in section, of atubing headstructure embodying another form of the invention.

More particularly describing the invention, reference numeral I0generally indicates the upper end of the outer string of a Well casing.Inwardly of this is an inner casing. H and. inside the inner casing thetubing I2.

Supported on the upper end of the casing H is a landing base [4 abovewhich is: a casing head [5. The parts are secured together by means ofwelds 16.

The casing head l5 isv tubular, being provided with a central opening[8, and is formed to provide an inwardly extending shoulder H) whichforms a support for a slip bowl 20 Suit able recesses 22 are provided inthe wall of the casing head to establish communication between the lowerend of the casing head and the threaded openings 23 to which may be.connected lateral flow lines.

The slip bowl 20 supports the. usual slips: 25 which have serrated innerfaces for engaging and supporting the casing H.

Mounted in the upper part of the bore of the casing head ['5 is anannular packing or sealing meansgenerally indicated by numeral 21 which,in the form shown, comprises a metal ring 28 adapted to rest on theupper end of the slip bowl. This ring is provided with a pair of taperedshoulders 29 and a central upstanding flange 3%]. Above the ring 28-there is positioned a packing compressing ring 32 provided with twodepending flanges 33 defining a central recess 34 of a size to receivethe upstanding flange 33 on the ring 28. Suitable packing of any wellknown type is positioned between the two rings and is indicated by thenumerals 35, the packingbeing divided into an inner and an outer ring,one being adjacent the inner surface of the bore [8 of the bowl and theother being ad'- jacent the outer surface of the casing II. A pluralityof screws 36 are provided for initially compressing the packing.

Means are provided for holding the compressionring 32 in place and forurging the ringtoward the ring 28-. This means comprises a plurality oflock screws 38, preferably three in number, which are located apart. Thescrewseach have an enlarged threaded portion 39 which is threadedlyreceived in a bore 40 extending radially of the casing head. The innerends of these screws are provided with a beveled head 42 adapted to bearagainst the tapered upper surface 43 of the compression 3 ring 32.Outwardly of the threaded bore 40 is a counterbore 44 which receives apacking gland comprising the packing 45 and a threadedly mounted bushing46.

Mounted on the casing head I- is a tubing head 50 and on this an adapter52. The casing head, tubing head and adapter are provided withappropriate end flanges as shown through which, it will be understood,bolts (not shown) extend for fastening the elements together in thecustomary manner. Between each pair of flanges is an annular deformablepacking ring element 53.

The casing l I extends through the casing head l5 and up into the tubinghead 50 for a limited distance. Means are provided for packing off orsealing between the inner wall of the tubing head 50 and the upper endof the casing I i, such sealing means including an annular packing 55and a packing compression ring 56. Extending radially of the lowerflange 51 of the tubing head are a plurality of lock screws 38a whichare similar to the screws 38 described in connection with the casinghead. The lock screws in the tubing head bear against a tapered surface58 at the lower outer portion of the packing compression ring 56 so thatthe screws can be utilized to compress the packing 55 and hold thepacking means in sealing engagement with the casing and head.

This construction provides a double seal for the casing l l, the upperseal located in the lower portion of the tubing head serving to preventescape of fluid pressure from interiorly of the casing H to the annularspace surrounding the casing and the lower seal 39 serving to preventescape of fluid pressure upwardly from the annular space between theouter casing l0 and the inner casing II. The seals thus prevent highpressure fluid reaching the flanged joint between the two head members,with the result that this joint is not subjected to high pressures whichwould leak past seal 53.

In order to provide for testing the efiectiveness of the two sealsagainst the casing and the seal 53 between the heads, the tubing head 50is provided with a radially extending passageway 60 to the outside ofthe head. This passageway may be screw threaded at 6| to accommodate apipe 62 and suitable test equipment which has not been shown.

The tubing head 50 is provided with a tapered seat 65 which accommodatesand supports a tubing hanger 66 threadedly secured at the upper end oftubing I2. Mounted in the hanger is a short extension of the tubingindicated by 12 which projects into the adapter 52. The tubing hanger 66has peripheral grooves which carry external packing rings 61 which arecompressed against the face 65 of the tubing head and serve to effect aseal between the head and the tubing above the vents B8. The tubinghanger is held down by lock screws 38b which are in all respects exceptsize similar to the lock screws 38 heretofore described.

Mounted in adapter 52 is a packing or seal means which comprises theannular packing H and a packing compression ring 12. The ring is made tocompress the packing by the lock screws 38c.

With this construction the high pressures which may exist in theinterior of the tubing I2 and in the annular space between the tubingand the casing H are prevented from reaching the interior of the tubinghead and adapter in the region of the flanged joint between the members,with the result that the packing 53a is not subjected to these highpressures, nor are the bolts extending through the flanges placed underan unnecessary strain.

The annular space at the top of the tubing head, indicated by numeral15, may also be tapped by means of a passageway 16 extending through thelower flange of the adapter, as shown, or a similar passage may beprovided in the upper flange of the tubing head.

It will be apparent that the above described construction provides acasing and tubing head structure in which the elements may be readilyassembled about the upper end of the pipe and in which the highpressures of the inner casing and tubing are prevented from reaching theflange joints between the individual head elements. At the same time thepacking or sealing means may be adjusted from a point outside of thehead and, if necessary, the packing means sealing the inner casing isreadily accessible without disturbing the casing. In addition, the sealsas well as the flanged joint may be tested.

In Fig. 2 there is shown a modified form of the invention wherein thetubing head member, which is similar to the tubing head shown in Fig. 1indicated by numeral 50a, supports an adapter head having a dependinginner threaded flange 8| in which is mounted a packing retaining ring 82which supports packing 83. Above the packing is a packing compressionring 84 which is urged against the packing by a lock screw 38d.

In Fig. 3 there is shown another form of packing means for sealing offthe upper end of the tubing or short section of tubing l2 whichcomprises a plate-like member 85 which is bolted (not shown) to thetubing head Eta and between it and any suitable coupling 86. This plateelement 85 has a depending annular flange or ring 8'! provided with aseat 88 for accommodating packing 89. The packing is compressed by apacking compression ring 9%) which is urged against the packing by ascrew lock 38c.

In the forms of the invention shown in Figs. 2 and 3, the tubing head50a is provided with a passage 92 providing communication between theexterior of the head and the annular space between the seals interiorlyof the head for test purposes. A plug 93 is shown closing the passage.The constructions shown in Figs. 2 and 3 provides two constructions forsealing off the tubing above the lower seal at the tubing hanger inwhich the overall height of the head structure is reduced relative tothe construction shown in Fig. 1. The plate 85 of Fig. 3 may be used inplace of a special adapter head.

Although the invention has been particularly shown and described, it iscontemplated that various changes and modifications can be made withoutdeparting from the scope thereof as set forth in the following claims.

I claim:

1. In a casing and tubing head structure, a tubular casing head, atubular tubing head mounted on said casing head, a tubular adaptermounted on said tubing head, seal means between said heads and adapter,a casing extending upwardly through said casing head and terminating inthe lower portion of said tubing head, a tubing extending upwardlyinside said casing and into said adapter, suspension means in saidcasing head for said casing, sealing means in said casing head abovesaid suspension means between the inner wall of said casing head and thecasing, sealing means in the tubing head between the inner wall of saidhead and said casing, suspension means in said tubing head above saidcasing for said tubing, sealing means in said tubing head between theinner wall thereof and said tubing, and sealing means in said adapterbetween the inner wall thereof and said tubing.

2. In a casing and tubing head structure, a tubular casing head, atubular tubing head mounted on said casing head, a tubular adaptermounted on said tubing head, seal means between said heads and adapter,a casing extending upwardly through said casing head and terminating inthe lower portion of said tubing head, a tubing extending upwardlyinside said casing and into said tubing head, suspension means in saidcasing head for said casing, sealing means in said casing head abovesaid suspension means between the inner wall of said casing head and thecasing, sealing means in the tubing head between the inner wall of saidhead and said casing, a tubing hanger at the upper end of said tubingwithin said tubing head and in sealing engagement therewith, a tubingnipple threaded into the upper part of said hanger and extendingupwardly into said adapter, sealing means in said tubing head betweenthe inner wall thereof and said tubing, and sealing means in saidadapter between the inner wall thereof and said tubing nipple.

3. In a tubing head structure, a tubular tubing head member, a tubularfitting member mounted on said tubing head member, a tubing extendingupwardly into said tubing head member, tubing suspension means in saidtubing head member suspending said tubing and providing a seal betweenthe same and said tubing head member, a tubing nipple detachably mountedin said suspension means and extending into said tubular fitting member,seal means in said fitting member between the inner wall thereof andsaid tubing nipple, and means in said fitting member extending to theexterior thereof adjustably to position said seal means in operative orinoperative position.

JOHN W. THATCH.

-REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,976,238 Long et a1 Oct. 9, 19342,094,690 Wickersham et a1. Oct. 5, 1937 2,178,700 Penick et al. Nov. 7,1939 2,187,839 Penick et a1 Jan. 23, 1940 2,232,884 Penick et al Feb.25, 1941 2,284,983 Minor June 2, 1942 2,306,102 Penick et al Dec. 22,1942 2,357,411 Leman et a1. Sept. 5, 1944 2,456,081 Penick Dec. 14, 1948

